Multiple (condenser) microphones 'in parallel' ?

[danci1973]

This is just a very basic idea and I'm not really at home with electronics, so please bear with me...

I have a hands free phone installation in my car and I'm a bit unhappy with the microphone pick-up. Possibly the basic problem is the microphone location, so I thought about adding one (or two) extra microphones 'in parallel' and mount those in a (hopefully) better position - something like **broken link removed**.

The hands-free box only has one microphone input, so I need a way to join all these mikes together and assuming the OEM mike is a 2-wire condenser capsule, just connecting the capsules in parallel probably won't work.

Would something really simple like this work?

Thanks in advance,

Danilo

 

[4pyros]

I think you would need preamps for all three and then mix them.

 

[audioguru]

You do not show condenser microphones that need an external 48V supply to bias their diaphragm. Instead you show electret microphones that have the 48V built into their electret material.

Your idea of numerous microphones will cause them all to pickup background noise but only the one closest to you will properly pickup your voice. A boardroom conference system uses numerous mics but has a mic mixer that turns on only the one mic that picks up the loudest sounds.

Another problem is that the "mic input" has a DC voltage to power the Jfet inside the electret mic and the DC will damage the volume controls.

Move your single mic so it is closer to your mouth (how about using a headset mic?).

 

[chemelec]

At the VERY LEAST, You need a Capacitor on the Wiper of Each Pot going out to the Mic Input.

Otherwise Each Control will Reduce or Increase the Outputs of the Other Controls.

 

[danci1973]

You do not show condenser microphones that need an external 48V supply to bias their diaphragm. Instead you show electret microphones that have the 48V built into their electret material.

A sad before I'm not an electronics expert or an audio guru, but my research so far led me to believe an electret microphone is a type of condenser microphone.

**broken link removed**
http://en.wikipedia.org/wiki/Electret_microphone

Your idea of numerous microphones will cause them all to pickup background noise but only the one closest to you will properly pickup your voice. A boardroom conference system uses numerous mics but has a mic mixer that turns on only the one mic that picks up the loudest sounds.

Good call. I'm afraid constructing something like that is a bit too complex for me, though.

Another problem is that the "mic input" has a DC voltage to power the Jfet inside the electret mic and the DC will damage the volume controls.

Couldn't I just de-couple that DC with another electrolyte capacitor?

Move your single mic so it is closer to your mouth (how about using a headset mic?).

OEM mic is not movable, so I could only install another and use (just) that one...

I don't like the idea of driving around with the headset on my head all the time - but putting it on when I get a call defeats the whole 'hands-free' purpose.